Ok
I've got a Winchester 1300 defender ,8 shots,18 inch bbl.I'd like to improve it,maybe making it into a decent slug type tactical gun for the possibile y2k unpleasantness.

It's pretty much stock, with the exception of sling swivels. With a budget of say 250 bucks,what would you folks suggest I do to improve it? Now before you say sell it and get an 870,I don't want to.I used it to dissuade a rather irate dude from doing me harm once,so it has sentimental value.